FIELD: equipment for well repairs, particularly, devices for expansion of longitudinally corrugated metal patches for reconditioning of sealing of casing strings of oil, water and gas wells. SUBSTANCE: mandrelling head consists of body, conical punch, floating sectors located on self-sealing collar. Conical slips are located movable in axial direction between conical punch and floating sections on body by means of dovetailing. Slots located between conical slips are displaced through half of their width relative to slots located between floating sectors. Mandrelling head has changeable limiters of conical slips. In building up of excessive pressure in system, punch is preliminarily expanded by conical punch, then by conical slips as intermediate expansion, and finally by floating sectors. EFFECT: higher quality of conjugation of patch with casing string and increased operating reliability of device. 3 dwg
